1. Field of the Invention
The invention relates to a apparatus and method for changing motor oil in an internal combustion engine having an oil pan or similar oil reservoir. Such reservoirs can be found in automobiles, trucks, tractors, heavy earth moving equipment, military equipment, or the like. More particularly, this invention relates to methods in which spent or dirty oil is expediently removed from the oil pan and analyzed as to amount and condition, the lubrication passages thereafter flushed with flushing fluid to remove contaminants, and then the lubrication system crankcase and oil pan are refilled with a measured amount of fresh oil appropriate for the engine.
2. Background of the Relevant Art
The benefits of routine oil changes in an internal combustion engine are well known. Routine oil changes have been shown to increase engine life and performance. With repeated prolonged use, motor oil builds up suspended particles, metallic and non-metallic, from the abrasive and adhesive wear of engine parts against one another and from products of incomplete combustion and improper air intake. The particles in turn cause abrasive wear of the engine bearings, piston rings and other moving parts and the reduction of the motor oil lubricity as various additives and lubricating components become depleted. This adversely affects engine performance and if left unchanged can destroy or cripple the engine performance. It is recommended by at least one oil manufacturer that the level of total solid concentration be limited to levels below 3.0% with levels of silica being present in amounts lower than 25 parts per million and sodium in amounts lower than 200 parts per million.
To obtain satisfactory engine performance, and maintain solids concentration levels in the motor oil lower than the recommended 3.0%, changing the motor oil in an internal combustion engine is a necessary, but an undesirable, dirty and time-consuming task. In currently designed vehicles, the oil pan serves the purpose of a reservoir for circulation of engine oil. Engine lubrication is generally accomplished through a gear-type pump. The pump picks up engine oil from the oil pan sump, where oil is drawn up through the pick-up screen and tube, and passed through the pump to the oil filter. The oil filter is generally a full flow paper element unit. In some vehicles, an oil filter bypass is used to insure adequate oil supply, should the filter become plugged or develop excessive pressure drop. Oil is routed from the filter to the main oil gallery. The oil gallery supplies valve train components with oil, and by means of intersecting passages, supplies oil to the cam shaft bearings. Oil draining back from the rocker arms is directed, by cast dams in the crank case casting, to supply the cam shaft lobes. Oil also drains past specific hydraulic lifter flats to oil cam shaft lobes directly. The passages supplying oil to the cam shaft bearings also supply the crank shaft main bearings through intersecting passages. Oil from the crank shaft main bearings is supplied to the connecting rod bearings by means of intersecting passages in the crank shaft. The front cam bearing can include a slot on its outside diameter to supply oil to the cam sprocket thrust face. In some engines, many internal engine parts have no direct oil feed and are supplied either by gravity or splash from other direct feed components. A bypass valve can also be disposed in the oil pick-up screen to insure adequate oil flow if the screen should become restricted. A pressure regulator valve, sometimes located in the oil pump body, maintains adequate pressure for the lubrication system and bypasses any excess back to the suction side of the pump. Oil from the pump passes through the filter before going to the engine oil galleries. In the filter, the oil passes through a filtering element where dirt and foreign particles are removed.
To remove the contaminated oil, the drain plug, generally located in the lowermost region of the oil pan, is opened. The spent oil containing suspended particles is permitted to flow under gravity out of the pan into a suitable receptacle. After the spent oil is removed, the plug is replaced and fresh oil is added to the engine usually through a separate opening in the engine valve cover. The process of gravity drainage does not remove all of the spent oil with its metallic and non-metallic particulates which stick to the oil pan container walls, as well as engine components such as the crank shaft, connecting rods, pistons and the like which are exposed to the motor oil spray lubrication. These particles remain to be mixed with fresh motor oil. Thus the concentration of contaminants is lowered by dilution and only a part of the total contaminates are actually eliminated.
The oil change process is essentially the same whether performed at home, at service stations or at one of the various oil change centers which have opened in recent years. The flow rate, or time required for oil drainage, is the same for each of these locations, because it is limited by the size of the drain plug aperture and the force of gravity. Service stations and other locations simplify the process of oil drainage with the use of hydraulic racks, special oil collection receptacles and the like. However, this specialized and expensive equipment is not readily available to the typical automotive owner who may wish to change the oil in his vehicle. It has been estimated that the retail market of oil is approximately 2.83 billion quarts or approximately 700 million gallons. The do-it-yourself individual has been found to be price sensitive, and tends to distrust the quality of service stations and other oil change centers. The do-it-yourself individual typically believes that if you want a job done right, you do it yourself. However, the current design of vehicles does not lend itself to do-it-yourself oil changes in a convenient clean and effortless manner. Many vehicles have low ground clearance making it difficult to access the oil drain plug for removal of the spent oil, and also making it difficult to collect the oil without contaminating the surrounding environment.
Regardless of the manner in which oil change is accomplished, it has long been appreciated that engine oil consumption can be indicative of engine performance and general engine condition. Excessive oil consumption can be indicative of engine problems such as malfunctioning piston rings, leaking and sagging exterior gaskets and seals or a lack of integrity in seals between the oil passages and coolant system. Information about specific increases in oil consumption would be of value to the vehicle owner to assist him in scheduling appropriate engine maintenance and repair before minor engine problems become major mechanical failures which compromise engine performance and engine life and introduce engine oil contaminants to the environment either as products of combustion or as leakage which can indiscriminately contaminate surfaces of the exterior engine compartment, as well as road and garage surfaces.
Environmental protection is a prominent social issue in our present society. Therefore, it would be desirable to encourage that all oil changes be performed in the most environmentally safe manner possible. It is estimated that there are approximately 119 million privately owned passenger vehicles. These vehicles require approximately 360 million oil changes a year, using an average of 1.2 gallons per change based on an average oil change frequency of 2.94 times a year. This amounts to approximately 550 million gallons of motor oil changed per year. Of this amount, it is estimated that 70% of motor oil is installed by motorists themselves. It is believed that pursuant to present practice, the spent oil drained by motorists finds its way into spent household containers, such as milk cartons. The household containers are closed and disposed of in the garbage which can and will finally find its way into the local waste dump. As the household container deteriorates, the oil and its contaminates will eventually seep into the surrounding ground and any ground water below the dump site. It has been estimated that 300 million gallons of oil a year seep into U.S. soil creating serious potential ground water pollution problems. It would be desirable environmentally and economically if this oil could be collected and recycled. In order to motivate the do-it-yourself market, it is desirable in the present invention to make the collection of oil during oil changes effortless, clean and inexpensive.
In establishing a system for encouraging oil recycling and resource recovery, it is also highly desirable to provide an oil change system which is self-documenting. By this, it is meant that the system is capable of accurately measuring and recording the amount of spent oil removed from various engines and the amount of fresh oil introduced into these engines. Accurate records of the amount of spent oil collected can be valuable in producing any waste manifests required under existing environmental protection and/or resource recovery laws.
Such records would provide regulatory agencies with an accurate indication of an oil handler's compliance with existing laws. The records would also be valuable to the operator of any oil change service by providing him with documentation demonstrating his adherence to all applicable laws and an opportunity to assist his customers in evaluating the need for overall engine maintenance.
Conservation of energy and the trade deficit are also major issues in today's society. It is estimated that 250-360 million gallons of spent oil can now be easily collected and profitably recycled. The price of spent oil so collected is four dollars per barrel at best, while the price of crude oil is much greater at approximately $18.00 per barrel. Recycling easily collected spent oil could decrease the trade deficit by approximately 120 million dollars, while providing a profitable recycling economy of approximately 86 million dollars per year.
Therefore, it would be desirable to provide a method which accelerates removal of spent oil completely and easily from the crank case. It would also be desirable to provide a system which reduces the amount of spent oil handling as required in the conventional oil change service station. It would also be desirable to provide a system which permits accurate assessment of the amount of oil expended and recovered. Finally, it is desirable to provide a method which could be easily employed by all vehicle owners at a convenient location with all the benefits of the method of the present invention such as time savings, money savings, convenience, minimum exposure to motor oil, environmental protection, energy conservation, trade deficit reduction, and finally longer lasting, better performing engines.